1. Field of the Invention
This invention relates to a liquid droplet ejecting recording head, and more particularly, to a liquid droplet ejecting recording head used for an ink jet recording apparatus capable of ejecting a recording liquid, ink, to project the liquid droplets for recording.
2. Description of the Prior Art
Among known recording systems, the so-called ink jet recording method is recognized as a very useful recording system. The ink jet recording method is a kind of non-impact recording system substantially free from noise during recording and can record at a high speed and further the recording can be made on plain paper without any particular fixing treatment.
Heretofore, various ink jet recording methods have been proposed. Some are practically used and some are still under development.
Ink jet recording methods comprises projecting droplets of a recording liquid, so-called ink, by any of various principles of action and depositing the droplets on a record receiving member to conduct recording.
Among ink jet recording methods, the method disclosed in Japanese Patent Laid Open No. Sho 54-51837 or Deutsche Offenlengungsschrift (DOLS) Nr. 2843064 has a feature that heat energy is applied to a liquid to eject liquid droplets, that is, heat energy is utilized as an energy for forming liquid droplets. This feature is quite different from features of conventional ink jet recording methods.
According to the method as disclosed in the above-mentioned patent applications, when a liquid is actuated by heat energy, the liquid is subjected to a state change including a rapid increase in volume and the resulting actuating force serves to eject liquid droplets from an orifice at the tip of the recording and the ejected droplets are deposited onto a record receiving member.
The ink jet recording system of the above mentioned DOLS 2843064 has advantages that the construction of an apparatus for conducting the recording is simpler than that of conventional ones and the system can effect a high speed recording when the ejecting nozzles are arranged in the form of multi-array. However, this system is not so good with respect to durability of the apparatus for conducting recording according to this system. The apparatus employs an electrothermal transducer as means for applying thermal pulse to the recording liquid, and therefore, the transducer is sometimes oxidized and deteriorated or a scorched recording liquid component is deposited on the transducer during its repeated use in contact with the recording liquid, and furthermore, the recording liquid tends to be electrolyzed. As the result, ejection of the recording liquid is sometimes disturbed.